Wednesday, March 24, 2010

Happy Ada Lovelace Day!

An explanation shamelessly taken from the Finding Ada website: "Ada Lovelace day is an international day of blogging... to draw attention to the achievements of women in technology and science."

If anything, I have a surfeit of inspiration; I am a woman in science who has been fortunate enough to have female science mentors from day one. Which makes six strong women who have directly mentored me in beginning my career in science, and at least twice that if you count those who didn't work directly with me on a day-to-day basis but provided support and guidance. Not to mention the myriad famous women-in-science who I read about, and identified with or idolized to greater or lesser extents, or the multitude of relatives I have who went into nursing when that was about as close as a woman could reasonably get to science, without putting up a fuss (or my mother, who did put up the fuss, and probably has had the biggest hand in supporting my love for science). Like I said, a surfeit of inspiration. I have half a mind to write about a couple more people, in addition to my summary below, and if I do I might make some more general conclusions about women-in-science, but that all depends on how long my experiments take this afternoon.

That said, in honor of Ada Lovelace day, I'm writing about Barbara McClintock. She was awarded the Nobel Prize in Physiology or Medicine in 1983 for her discovery of 'jumping genes'. Her detailed work on genetics was absolutely ahead of its time: she was one of the first people to see meiotic recombination ('crossing over') events occur, she discovered the first DNA transposons, and she practically invented the concept of the distal enhancer or controlling element. In short, her work forced a transition from viewing DNA as a static molecule of inheritance to a dynamic molecule biochemically active within the cell and regulated in various ways. This at around the same time as the 'one gene one enzyme' hypothesis (it has since been rather spectacularly discredited by alternative splicing and noncoding RNAs) and the 'central dogma of molecular biology' (DNA is inherited, and transcribed into RNA which is translated to proteins -- and proteins are the truly functional parts of the cell -- which has also been rather spectacularly discredited). Biochemistry at the time, in other words, had not yet caught up to McClintock's ideas (it's arguable that it still hasn't quite gotten there, and the organization and dynamics of chromosomes is a very active field of study to this day).

McClintock was able to make the advances she did because she bridged cytology and genetics, and directly visualized chromosomes in the process of breaking and reattaching that takes place with every recombination or transposition. In other words, she was able and willing to pore over countless microscope slides, looking for the tiny breaks and joins in mitotic chromosomes, and changes in banding patterns that proved the jumps. Grueling, careful, detailed work to support her groundbreaking theories. However, in the middle of her career, she stopped publishing reports in major journals and instead communicated her findings only to a small group of friends and allies, because she felt her work was being ignored or discounted: "I stopped publishing detailed reports long ago when I realized, and acutely, the extent of disinterest and lack of confidence in the conclusions I was drawing from the studies." Ironic when so many of her theories were proven essentially correct, and largely generalizable, in the years following their discovery.

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